(1) Field of the Invention
The present invention relates to an image-forming apparatus provided with an automatic original delivery mechanism. More particularly, the present invention relates to an image-forming apparatus provided with an automatic original delivery mechanism having automatic original delivery means for automatically receiving and guiding an original set at an insertion opening to a copying position and discharging the original to the outside of the apparatus after the copying operation, in which the disposal of the original is facilitated when jamming or other delivery trouble of a copying paper sheet takes place.
Furthermore, the present invention relates to an original carrier sheet for carrying out the copying operation without damaging an original composed of a very thin paper or very thin sheet. More particularly, the present invention relates to an original carrier sheet which is applied to an image-forming apparatus provided with an automatic original delivery mechanism to prevent improper setting of an original.
(2) Description of the Related Art
Image-forming apparatus include a printer, a facsimile device, a copying machine and the like. An automatic original delivery mechanism of such an image-forming apparatus, for example, a copying machine, comprises a delivery device ordinarily arranged at the copying position and an original detector for detecting the original feeding timing or detecting the presence or absence of an original. The operation timing of the driving system for the original delivery device is generally the same as or synchronous with that of the driving system for a photosensitive drum and a copying paper sheet (paper sheet on which a copied image is formed), and the timing of feeding the original synchronously with the copying paper sheet is set by the original detector.
If a delivery trouble such as jamming is caused in the delivery of the copying paper sheet in the copying machine, the machine is stopped and after the jamming-removing treatment, that is, after the normal state has been restored, the copying operation is started again.
In the conventional copying machine, if jamming is caused, a copying paper sheet should be taken out of the apparatus and furthermore, an original should be taken out of the automatic delivery mechanism and be placed at the initial setting position again. This operation is very troublesome.
For eliminating the troublesome operation of taking the original out of the automatic original delivery mechanism, there has been proposed a copying machine capable of automatically discharging an original from the automatic original delivery mechanism when jamming or the like occurs (see Japanese Unexamined Patent Publication No. 55-156966 and Japanese Unexamined Patent Publication No. 59-106099). Even in the copying apparatus having the above-mentioned structure, a troublesome operation of resetting the original at the initial setting position cannot be eliminated.
This resetting of the original should be performed not only at jamming of a copying paper sheet but also at jamming of the original per se.
Not only ordinary document originals but also very thin paper originals, very thin sheet originals, small-size sheet originals and sheets originals having a special shape are used in the image-forming apparatus provided with the automatic original delivery mechanism, and in case of a special original as mentioned above, the copying operation is carried out through an original carrier sheet. As shown in FIG. 5, a conventional original carrier sheet 70 comprises a pair of sheet portions 72 and 74 having insertion top end sides thereof bonded together by a connecting portion 76. The sheet portion 72 is transparent and the copying face of a very thin original 78 supported confronts the sheet portion 72. In view of the bonding strength and the flexural elasticity, the connecting portion 76 of the conventional original carrier sheet 70 is formed to have a certain width and the top end side of the original 78 abuts on the bonding line (broken line 80 in FIG. 5).
When the original is delivered by using the original carrier sheet, an original-detecting switch of the delivery mechanism does not detect the top end of the original but the top end of the carrier sheet 70, and therefore, reading is not effected from the predetermined position of the original and there is a risk of dislocation of the image-forming position.
Of course, this dislocation or shear of the image-forming position is caused by the fact that it is not the top end of the original but the top end of the carrier sheet that is detected for the reading, and this dislocation can be prevented by staggering the reading time by the depth (length in the delivery direction) of the connecting portion between both the sheet portions in the carrier sheet. However, a changeover switch and a control device become necessary for this adjustment, with the result that the cost increases and the operation becomes complicated.
Furthermore, in the case where the above-mentioned original carrier sheet is used, even if the reading time can be staggered, it seldom happens that the top end side of the original abuts exactly to the connecting portion between both the sheet portions, and therefore, it is difficult to solve the problem of dislocation of the image-forming position.